Life of Pi: Grabbing the CG Tiger by the Tail
The first thing that director Ang Lee wanted to know was if a CG animal would be more or less real in 3-D. That's because once he committed to shooting Life of Pi stereoscopically (using the Cameron-Pace 3-D rig), the entire thrust of his movie rested on the believability of the Bengal tiger, Richard Parker. After all, most of Life of Pi takes place on a lifeboat at sea (shot on stage in a water tank against blue screen) with just the eponymous hero (Suraj Sharma) and the tiger.
Thanks to VFX supervisor Bill Westenhofer and his team at Rhythm & Hues, they not only passed the crucial 3-D test -- rendering Aslan just as he was -- but also pulled off the best possible photorealistic CG animal, far surpassing Aslan from The Chronicles of Narnia. In fact, R &H will be right in the hunt for the VFX Oscar as a result of the tiger's emotional arc. Parker exhibits such believable expression and detail, beginning with the way he uses the space underneath the tarp first as shelter and then to observe and control his turf; then the way the two companions overcome their mutual fear and the eventual kinship that transpires between them.
"We followed [Ang's] instructions and it looked real -- the 3-D gave it a little more presence and you could see more detail and it helped the believability," Westenhofer recalls. "He was also impressed that we didn't try to sweeten the deal by improving the hairs."
But that was only the beginning. Both Lee and Westenhofer were adamant about using a real tiger for reference as well as for part of the shoot. They didn't have to search too far because trainer Terry Le Portier, who supplies tigers for movies (Gladiator), had one that instantly caught Lee's eye: King, who proved to be the orneriest the director could've chosen.
"I wanted to set the bar where there was no way we could cheat," Westenhofer continues." I saw the wisdom of that when we were building the model of the CG tiger during pre-production and ran some tests. I think if we didn't have the real one to hold our feet to the fire it wouldn't have been as good. The other real advantage is that there is no way we would've ever gotten the reference that we had on set with us. We only had a real lion on Narnia for two days. On day one we took one of the lifeboats and put it on a gimbal in the tiger compound and put the blue screens up right away. We even put a fake camera they could rehearse with. All it took to film was to replace the camera with a real one."
From a tech standpoint, the biggest change to the R&H animation system was the skin simulation. Tigers are comprised of solid mass with loose skin hanging off it. They've got muscle that you can see coming through but they've got a lot of drapery of this loose skin hanging on top, so animators had to make a multi-pass skin solve that first would stick to the muscles and slide over and then another skin element that would hang from that.